1. Field of The Invention
Applicant's invention relates suture knots, methods and apparatuses employed in forming suture knots, and methods of use of such knots and apparatuses.
2. Background Information
Most (but not all) knots preferably exhibit the characteristic of not slipping or becoming untied during their normally anticipated use(s). The principle feature of a knot which is least likely to slip or unintentionally become untied is that of having more rather than fewer distortions of the filament which forms the knot within the bounds of the knot.
In the case of a slipknot, one segment of the filament which extends from the knot's free loop, through the body of the knot and to and including the terminus of the filament is referred to as the "standing part." For slipknots then, the more forced bends in the standing part as necessitated by the knot design, the more resistant to slippage and becoming untied the knot in its tightened state tends to be.
In the surgical field, suture knots most certainly should not ordinarily slip nor become untied under any circumstances. It is to knots to be used as sutures in surgical procedures to which Applicant's invention principally relates.
Presently, most suture knots used in surgical procedures are tied completely by hand or, in instanced where the fingers cannot reach, using surgical instruments. Certain apparatuses have been proposed which assist in forming suture knots. However, the prior apparatuses and associated methods of use provide assistance only in tying relatively simple knots or only small portions of more complicated knots.
At present, the most common knots used for sutures are the square and the surgeon's knots. The square knot is a simple knot, but difficult to fashion solely with surgical instruments such as are necessary in endoscopic surgical procedures. Once formed, the square not is not outstanding among knots insofar as resistance to becoming untied is concerned.
Impetus for developing improved knots along with practical methods and apparatuses for their formation arises from the relatively new field of endoscopic surgery. Endoscopic surgery involves making small incisions and passing telescope like instruments to the surgical site. Certain instruments involved permit visualization of internal structures while others effectuate the actual surgical procedure(s).
Current applications of endoscopic surgery include:
arthroscopic surgery--this form of surgery involves the introduction of instruments into joints, the most common such procedure involving the knee joint, while others involve inspection of many other joints; and PA1 abdominal surgery--endoscopic abdominal surgery is involved in removing gallbladders and appendices and in performing bowel resections. Gynecologists have been performing endoscopic operations on a regular basis in this country for over twenty years in the form of tubal sterilization procedures. These practitioners also use endoscopic procedures for diagnostic purposes, for freeing up adhesions between various pelvic organs and for correcting conditions leading to infertility. The numerous gynecologic procedures currently performed endoscopically include (1) the use of cautery or laser to destroy abnormal tissue areas, (2) removal of ovarian cysts, (3) removal of certain tumors from the uterus, (4) destruction of pain carrying nerve fibers in patients who have abdominal pain, and (5) procedures requiring knot tying such as bladder suspension operations, hysterectomies and removal of ovaries.
It is anticipated that within the next three to five years 50% of operations that are currently being performed through large abdominal incisions will be performed endoscopically. The advantages of endoscopic surgery are (1) the procedures can be performed on an outpatient, day surgery basis thereby decreasing the cost of prolonged hospitalization and (2) shorter convalescence which allows patients to return to work within a day or two of surgery.
Further advancements and greater utilization of endoscopic procedures is currently hampered by the inability to easily tie knots within the abdominal cavity and other relatively inaccessible involved spaces. Currently, surgery is performed by inserting the needle into a hollow body cavity, passing the needle through the tissues, bringing the needle out to the exterior, manually developing a knot and then locking the knot into position by traction on the end of the apparatus which pulls the thread through a hollow tunnel running the length of a 3 mm nylon tube.
It is anticipated that the inventions disclosed herein will greatly facilitate the tying of extra-corporeal knots (knots being tied outside the body to thereafter be slipped into position). This, in turn, will facilitate and expedite such procedures as: Marshall Marchetti Krantz procedures; uterine suspensions; hysterectomies; appendectomies; and bowel resections. Surgeons required to tie knots at the back of the throat, in the chest cavity, in the placement of heart valves, in brain surgery and in the repair of ligaments (i.e. in arthroscopic surgery) will also be greatly served by the inventions disclosed herein.
It is anticipated that the best mode of practicing all embodiments of Applicant's inventions will involve formation of a protoknot prior to beginning surgery leaving only the passage of one filament element through a specified path for completion of the suture knot. In this manner, the knots will, in all but the rarest of instances, be perfectly formed. This will also allow the surgeon to place sutures more quickly thereby lessening the time that the patient is under anesthesia which has obvious advantages. Absent the complete compliment of Applicant's inventions as disclosed herein, surgeons will be required to use the disclosed knots, if at all, only after the difficult task of tying them completely by hand with the concomitant likelihood of incorrectly forming the knots and thereby increasing the likelihood of slippage.
Prior-issued patents which are known to Applicant and which relate either to surgical knots or to knots in general include the following:
U.S. Pat. No. 2,705,656 issued to Shockey on Apr. 5, 1955 describes a knot tying device for use in mending broken wires as are used in wire sound recorders. The Shockey device constructs a square knot from two loose ends of wire.
U.S. Pat. No. 3,580,256 issued to Wilkinson on May 25, 1971 describes a pre-tied suture and method of suturing that utilizes a pair of butterfly loops in a pre-formed configuration. This pre-tied suture encapsulates the two butterfly loops with a transparent casing and allows the end portions of the suture material to extend from the loops out of the casing. A void remains through the interior of the loops through which one end of the suture material may be passed to finish the formation of the knot. The butterfly loops may then be tightened, the casing forced to disintegrate around it. The knot may then be pulled into a formation that involves a square knot.
U.S. Pat. No. 4,923,461, issued to Caspari on May 8, 1990 discloses a method of suturing for arthroscopic surgery that incorporates a hollow needle and a mechanism whereby suture material may be fed through the hollow needle. Caspari prescribes a series of steps from which a suture knot results.
U.S. Pat. No. 4,602,635, issued to Mulholland on Jul. 29, 1986 discloses a "remote surgical knot tier and method of use" intended for arthroscopic surgery. Mulholland uses a rod-like device through a portion of which extends suture material. Mulholland prescribes a series of steps which ultimately results in the formation of a "square" knot.
U.S. Pat. No. 4,621,640, issued to Mulholland on Nov. 11, 1986, discloses a mechanical needle carrier which is intended to hold and position a surgical needle during arthroscopic surgery. This device is intended to set a stitch at a remote location within the tissue cavity and to then release the needle so that it might be withdrawn from the cavity leaving the suture stitch in place.
U.S. Pat. No. 3,834,395 issued to Santos on Sep. 10, 1974, describes a knot tying instrument which utilizes a pair of elongated rods that face each other and are physically attached to one another in a scissor-like arrangement. The Santos device is designed to tighten a suture knot within in a tissue cavity.
U.S. Pat. No. 2,594,086, issued to Larzelere on Apr. 29, 1952, discloses a surgical instrument designed to tie knots in sutures within body cavities. The Larzelere device is in the nature of an elongated rod with means for engaging two ends of a suture filament so as to direct force appropriately for tightening a square knot.
U.S. Pat. No. 4,711,476, issued to Hansen on Dec. 8, 1987 discloses a knot and various methods for the formation thereof.
Significant limitations relating to previously known apparatuses and methods for the formation of suture knots include: (1) being limited to the formation of simple knots such as the square knot; (2) involving knots which require the manipulation of both ends of a length of suture filament which, accordingly, cannot be substantially tied prior to surgery or merely slipped into place; and (3) requiring multiple manipulations outside of the surgical incision with loops thereby formed being afterwards coaxed toward the suture site.
In addition to the knots and apparatuses disclosed in the above-referenced patents, a knot known as the "Roeder loop" is disclosed by K. Semm in the Operative Manual for Endoscopic Abdominal Surgery, Year Book Medical Publishers, Inc., 1987:23-31 which publication will be made available in an information disclosure statement to accompany this application.